Rotary switch



Dec. 1, 1964 J. M. COBB ETAL 3,159,722

ROTARY SWITCH Filed March 20, 1961 3 Sheets-Sheet l INVENTORS Jesse M.Cabb y Harry J. Krol Qfflys Dec. 1, 1964 J. M. COBB ETAL 3,159,722

I ROTARY SWITCH Filed March 20, 1961 3 Sheets-Sheet 2 INVENTORS Jsse MCobb Harry J. Krol aizf'ys Dec. 1, 19 J. M. COBB ETAL ROTARY SWITCHFiled March 20, 1961 3 Sheets-Sheet 5 INVENTORS Jesse M. Cobb arry J.k'rol aziy's BY QM I A a u no llrhblllllll i am United States Patent3,159,722 RQTARY SWITCH Jesse M. Cobb, Glenview, and Harry J. Krol,Arlington Heights, 111., assignors to Indak Manufacturing Corp.,Northhroolr, Ill., a corporation oi Iilinois Filed Mar. 20, 1961, Ser.No. 96,790 3 Claims. (Cl. 260-41) This invention relates to new andimproved switches of the rotary type and having a plurality ofpositions. Such switches find applications, for example, in theautomotive field, for use in controlling heaters and other electricalequipment.

One object of the present invention is to provide a new and improvedswitch having a highly advantageous and economical detent and springarrangement which is formed integrally with the rotor of the switch.

A further object of the present invention is to provide a rotary switchhaving an improved contact construction, insuring the maintenance ofsubstantially uniform contact pressure in all positions of the switch.

Another object is to provide a new and improved switch having a contactconstruction which gives the eifect of three-point distribution of thecontact pressure between the rotary contactor and the contact points,even though, in some positions of the switch, only two contact pointsmay be in engagement with the contactor.

Still another object is to provide a new and improved switch which isdurable in construction and eifective in operation, yet is easy tomanufacture and low in cost.

Further objects and advantages of the present invcntion will appear fromthe following description, taken with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a switch to be described as anillustrative embodiment of the present invention.

FIG. 2 is a rear view of the switch.

FIG. 3 is a longitudinal section, taken generally along a line 3-3 inFIG. 2.

FIGS. 4, 5, 6 and 7 are cross sectional views, taken generally asindicated by lines and arrows 4-4, 5 5, 6-6 and 7-7 respectively, inFIG. 3.

FIGS. 8 and 9 are fragmentary sectional views, taken generally along thelines 8-8 and 99 in FIG. 7.

FIG. 10 is a rear view of the rotor for the switch of FIG. 1.

FIG. 11 is a side view of the rotor, taken as indicated by the line 1111in FIG. 10.

FIG. 12 is a top viewof the rotor, taken as indicated the contactor inits high position, in which the contactor engages three contact points.

' FIG. 16 is a fragmentary enlarged section taken gen- ;erally along aline 16-16 in FIG. 15.

FIG. 17 is an elevational view of a modified switch, representinganother embodiment of the invention.

FIG. 18 is a central longitudinal section of the switch of FIG. 17. 7

FIGS. 19, 20 and 21 are cross sectional views, taken generally alonglines 19-19, 2ll20 and 21-21, re

spectively, inFIG. 18, FIGS. 19 and 21 being drawn to enlarged scales.

3,159,722 Patented Dec. 1, 1964 It will be seen that FIG. 1 illustratesa rotary switch 30 which will find many applications, but is of ageneral type which is often employed in automotive services forcontrolling electrically driven accessories such as heaters or the like.The illustrated switch 30 has a casing 32 which is generally of a squareshape. A threaded bushing 34 projects forwardly from the casing 32 andmay be employed for mounting the switch on a control panel bracket, orthe like. The switch has a shaft 36 which extends forwardly from thebushing 34 and is rotatably mounted therein.

In this case, the rear of the casing 32 is closed by a terminal plate orboard 38 which is made of electrically insulating material. The plate 38may be secured to the casing 32 by means or" a plurality of tabs 0rflanges 48 which are formed on the casing and are bent over behind theplate 38. To locate the plate 38, notches 42 may be formed in the edgesof the plate to receive the tabs 40.

The illustrated switch 30 is provided with three terminals in the formof lugs or angle members 44, 45 and 46, secured to the insulating plate38. However, it will be understood that the number of terminals may bevaried according to the number of circuits to be controlled by theswitch.

As shown to advantage in FIG. 3, the switch 30 has a rotor 48 which ispreferably molded in one piece from nylon or some other suitable plasticmaterial. The shaft36 may be made of metal and may be mounted in a bore59 formed in the rotor. The illustrated shaft 36 is provided with aserrated rear end portion 52 which may be pressed securely into the bore56 so as to be retained therein.

As clearly shown in FIG. 5, a generally ring-shaped contactor 54 ismounted on the rotor 48. It will be seen that the rotor 48 has a rearportion 56 which is received within a generally circular opening 58 inthe contactor 54. Notches 60 and 61 are formed in the edge of theopening at diametrically opposite points to receive outwardly projectingkeys or lugs 62 and 63, formed on the rotor member 56. Engagement of thekeys 62 and 63 with the notches 60 and 61 insures that the contactor 54will rotate with the rotor.

The illustrated switch 30 is provided with three contact points 66, 67and 68 which are mounted on the insulating plate 38 and are riveted orotherwise secured to the terminal lugs 44, 45 and 46, respectively. Inthe various positions of the switch, the contactor 54 is engageable withthe contact points to establish circuits therebetween, as will bedescribed in greater detail shortly.

It will be seen that the rotor 48 has a rearwardly projecting journal orpin 70 thereon. An opening 72 is formed in the insulating plate $8 forrotatably receiving the journal 76. In the illustrated switch 30, thecontactor 54 is biased rearwardiy against the contact points and 68, bymeans of a spring 74 which acts between the contactor and a pair of arms76 on the front portion of the rotor. Preferably, the spring 74 is ofthe conical coil type tapering in diameter from front to rear.Rearwardly projecting lugs or flanges 78 are formed on the arms '76 toretain the front end of the spring 74.

The rotor 48 is movable to a plurality of positions and is detented andlocated in each of such positions by a novel detent arrangement 80,comprising a pair of detent projections 82, formed on the rotor 48, anda series of detent grooves or troughs 84, 85 and 86, formed in the frontwall 88 of the casing 32. In this case, there are three detent groovesto locate the rotor 48 in three diifen ent positions, but it will beunderstood that any desired number of detent grooves may be provided, inaccordance with the desired number of positions of the switch.

to As shown to advantage in FIGS. 9 and 10, each of the detentprojections 82 is formed on the central portion of a flat generallysemicircular web or arm 90 which is formed integrally with the plasticrotor 48. The webs or arms 99 are sufliciently thin to be flexible andresilient,

so as to serve as springs for the detent members 82. T he detent grooves84, 85 and 86 are actually in the plane of the front Wall 88 and aredefined by rearwardly project ing rounded humps 92 which extend betweenthe detent grooves. As the rotor 48 is turned, the bumps )2 push thedetent members 82 rearwardly, with the result that the arms 96 areflexed. The rear portion 56 of the rotor 48 engages the insulating rearplate 38 and limits rearward motion of the rotor '48. The coil spring 74biases the rotor 48 forwardly so as to maintain the detent members 82 insnug engagement with the detent grooves 84, 85 and 86 in the variouspositions of the switch.

A rearwardly projecting lug 94 is formed on the rear side of each of thewebs or arms 90, to the rear of the corresponding detent projection 82.A groove 96 is provided in each of the lugs 94 to retain and locate thefront coil of the spring 74.

A already indicated, the contactor 54 is ring shaped and is slidablyreceived on the rear portion es of the rotor 48. e The keys 62 and 63 onthe rotor are of different sizes, so that the contactor 54 will fit onthe rotor in only one position. p p V The contactor 54 is preferablyformed from sheet metal. it will be seen that the contactor 54 has acentral portion 98 which represents the original plane of the sheetmetal. Three contact segments ltll, 102 and 103 are formed into a planewhich is displaced rearwardly from the plane of the central portion 93,so that the segments 101, 102 and 103 will be engageable with thecontact points 66, and 68 on the insulating rear plate 38. Between thecontact segments 101, N2 and 1%, the contactor 54 is formed withnoncontacting segments 165, 105 and 167 which are formed into a planewhich is displaced forwardly from the plane of the central portion 98.

When the switch is in its off position, as shown in FIGS. 5 and 13, thecontact point 66 is opposite the .noncontacting segment 107 and thus isout of engagement with the contactor 54. Normally, the contact point 66is connected to the hot lead of the battery, or other power source,through the lug 44. Thus,the lug 4 is marked with the letter B on therear plate 38, as shown in FIG. 2. The lug 45 is marked with the letterL representing low, while the lug 46 is marked with the letter H,representing high. The lugs 45 and 46 are connectedto the contact points6'7 and 68, respectively. In the oil position, one of the arms 76 on therotor 4S engages a stop :l ltl which is formed inwardly from one wall ofthe casing 32. The contact point 67 is opposite the noncontactingsegment 105, while the contact point 68 is opposite the noncontactingsegment 1%.

To engage the contacting segments 101, 1&2 and 103, insulating plate 38is formed with a plurality of forwardly projecting insulating points ormember'slll, 112, 113 and 114 which may be produced by partiallypunching or extruding disc shaped elements from the plate. In this casethere are four insulating points, but the number may be varied to suitthe requirements of the switch. In the oil position of the switch, thecontact'segments 101, 102 and 103 are engagedby the insulating points111, 112 and 113, respectively. Thus, these are three points of contactwith the contactor 54. This arrangement insures that the contactor willnot have any tendency to rock relative to the rotor 48.,

In the next position of the switch, which may be designated the lowposition, the rotor '43 is turned to bring the contactor 54 to theposition shown in FIG. 14. The battery contact point at now engages thecontact segment 101, so that b'att ery current is supplied to thecontactor 54. The contact segment 102 engages the contact point 68.

so that this contact point and the lug 46 are connected to the battery.The contact point 67 is still opposite the noncontacting segment 105. Toprovide for three point contact with the contactor 54, the insulatingpoint 114 engages the contact segment 103. The insulating points 112 and113 are opposite the noncontacting segments 1G7 and 166, respectively,and thus are out of engagement with the contactor. The insulating point111 is opposite the contact segment 161 but does not engage such segmentbecause the insulating point projects forwardly to a lesser extent thanthe contact point 66 which is in engagement with the segment 181.

In the third position of the switch, which may be designated the highposition, the rotor 48 is rotated until the arm it engages a second stop116 formed inwardly from the casing 32. The battery contact point 66still engages the contact segment 101, as shown in FIG. 15. However, thecontact point 68 is now opposite the noncontacting segment Th7 and thusis out of engagement with the c'ontactor 54. The contact point 67engages the contact segment 193 so that the contact point 67 and the lug45 are connected to the battery terminal 44'. The Contact segment 16 2engages the insulating point 113 to provide for three point contact withthe contactor. The other insulating points are out of engagement withthe contact'or.

It will be apparent that the arrangement of the insulating point 111-114insures that there will be three points of engagement with the contactor54 in all of the 'positions of the switch. In this way, the contactpressure between the contact points and the contacto'r will be 'evenlydistributed, and there will be no tendency for the contactor to rockrelative to the contact points.

FIGS. 17-21 illustrate a modified switch 130 which is the same as theswitch 3601f FIGS. 1-16, except that the shaft 36 is replaced with ashaft 136 which is slidable longitudinally through the rotor 148. Therear end 'of the shaft 136 is connected to a flexible resilient wire 202which is adapted to operate a push-pull type control, such as an aircontrol valve or deflector for an automotive heater or the like. Thewire 202 is slidable within a protective flexible sheath 2% which may bein the form of a closely coiled helical wire. The rear portion of theshaft 136 isslidab-le within .a tubular guide 295 secured to theinsulating plate 138. It will be seen that one end of the sheath 2% isreceived within and secured to the rear end of the tubular guide 206. Acoupler 2% is employed to connect the rear end of the shaft 136 to thefront end of the wire 262.

The shaft 13s is noncircul-ar in cross section and is slidable within anopening 210 of corresponding shape in the rotor 148. In this instance,the shaft 136 has a flat 212 on one side and a keywa'y 214 on theopposite side. The opening 219 receives the shaft 136 with a closesliding fit so that the rotor 14% will rotate with the shaft 136.

In all other particulars, the switch may be the same as the switch 30.To the extent that the switches are the same, the same referencechanacters are employedin FIGS. l7-2l as in FIGS. 1-16.

It will be apparent that each of the illustrated switches is providedwith an effective and economical detent arrangement in which the detentinl'ernber's 82 are connected to the rotor by the integral flexible arms90 which serve as springs for the detent members. Another importantfeature resides in the manner in which the insulating points 111-114insure that the contac'tor will be engaged the true spirit and scope ofthe invention, as exemplified in the foregoing description and definedin'the following claims.

We claim:

1. In a switch, the combination comprising a casing, a plasticinsulating rotor mounted in said casing for rotation to a plurality ofpositions, contact means operable by said rotor, a plurality of detentchannels on said casing corresponding to said positions of said rotor, apair of plastic detent members engageable with said detent channels, and\a pair of thin flexible generally semicircular plastic arms resilientlyconnecting said detent members to said rotor; each detent member beingdisposed sub stantially midway between the ends of the correspondingsemicircular arm, the ends of each arm being connected to said rotor;said rotor, said arms and said detent memhere being formed integrallyfrom resilient plastic material.

2. In a switch, the combination comprising a casing, a plasticinsulating rotor mounted in said casing for rotation to a plurality ofpositions, a contactor rotatable with said rotor, a plurality of detentchannels on the front portion of said casing and corresponding to saidpositions of said rotor, a pair of plastic detent members engageablewith said detent channels, a pair of thin flexible generallysemicircular plastic arms resiliently connecting said detent members tosaid rotor, each of said arms having its ends connected to said rotor,each of said detent members being disposed substantially midway betweenthe ends of the corresponding semicircular arm, said arms and saiddetent members being formed integrally with said rotor,

contact means in said casing to the rear of said rotor and engageable bysaid contactor, and a spring acting between said contactor and saidrotor for biasing said contactor rearwardly against said contact means,while biasing said rotor forwardly to urge said detent members againstsaid detent channels.

3. In an electric switch, the combination comprising a casing, a rotorrotatably mounted in said casing, a contactor rotatable with said rotorand having a plurality of imperforate arcu-ate contact segments, aninsulating member mounted on said casing to the rear of said rotor, aspring biasing said contactor toward said insulating member, .aplurality of conductive contact points on said insulating member andengageable by said contact segments of said contactor, said contactpoints projecting forwardly from said insulating member, a plurality ofinsulating points projecting forwardly from said insulating member anddisposed thereon between said contact points and engageable by saidcontact segments, and detent means for detaining said rotor in aplurality of operative positions, said detent means being separate fromsaid contact segments and said contact point-s and insulating points,certain of said contact segments being engageable with certain of saidinsulating points while other of said contact segments aresimultaneously engageable with certain of said contact points in atleast one of said operative positions of said rotor, the engagement ofsaid insulating points with said contact segments being effective tomaintain three-point contact with said contactor to prevent excessiveand uncontrolled rocking of said contactor in its various operativepositions.

References Cited in the file of this patent UNITED STATES PATENTS1,663,779 Soreng Mar. 27, 1928 1,696,744 Wynran Dec. 25, 1928 1,828,433Norviel Oct. 20, 1931 1,855,612 Salinas Apr. 26, 1932 2,519,215 Appletonet a1. Aug. 15, 1950 2,530,006 Ellithorpe Nov. 14, 1950

3. IN AN ELECTRIC SWITCH, THE COMBINATION COMPRISING A CASING, A ROTORROTATABLY MOUNTED IN SAID CASING, A CONTACTOR ROTATABLE WITH SAID ROTORAND HAVING A PLURALITY OF IMPERFORATE ARCUATE CONTACT SEGMENTS, ANINSULATING MEMBER MOUNTED ON SAID CASING TO THE REAR OF SAID ROTOR, ASPRING BAISING SAID CONTACTOR TOWARD SAID INSULATING MEMBER, A PLURALITYOF CONDUCTIVE CONTACT POINTS ON SAID INSULATING MEMBER AND ENGAGEABLE BYSAID CONTACT SEGMENTS OF SAID CONTACTOR, SAID CONTACT POINTS PROJECTINGFORWARDLY FROM SAID INSULATING MEMBER, A PLURALITY OF INSULATING POINTSPROJECTING FORWARDLY FROM SAID INSULATING MEMBER AND DISPOSED THEREONBETWEEN SAID CONTACT POINTS AND ENGAGEABLE BY SAID CONTACT SEGMENTS, ANDDETENT MEANS FOR DETAINING SAID ROTOR IN A PLURALITY POSITIONS, SAIDDETENT MEANS BEING SEPARATE FROM SAID CONTACT SEGMENTS AND SAID CONTACTPOINTS AND INSULATING POINTS, CERTAIN OF SAID CONTACT SEGMENTS BEINGENGAGEABLE WITH CERTAIN OF SAID INSULATING POINTS WHILE OTHER OF SAIDCONTACT SEGMENTS ARE SIMULTANEOUSLY ENGAGEABLE WITH CERTAIN OF SAIDCONTACT POINTS IN AT LEAST ONE OF SAID OPERATIVE POSITIONS OF SAIDROTOR, THE ENGAGEMENT OF SAID INSULATING POINTS WITH SAID CONTACTSEGMENTS BEING EFFECTIVE TO MAINTAIN THREE-POINT CONTACT WITH SAIDCONTACTOR TO PREVENT EXCESSIVE AND UNCONTROLLED ROCKING OF SAIDCONTACTOR IN ITS VARIOUS OPERATIVE POSITIONS.